1. Field of the Invention
The present invention relates to an optical displacement meter for detecting a displacement of an object by a triangulation system.
2. Description of Related Art
In a triangulation system optical displacement meter, a surface of an object (hereinafter referred to as “workpiece”) is irradiated with light, and the reflected light thereof is received by a light-receiving element having one-dimensionally or two-dimensionally aligned pixels. A height of the surface of the workpiece can be measured based on a peak position of a light-receiving amount distribution obtained by the light-receiving element. It is thereby possible to detect a displacement of the workpiece (e.g., Japanese Unexamined Patent Publication No. 2008-96117).
In an optical-cutting system optical displacement meter, the workpiece is irradiated with band-like light having a linear cross section, and the reflected light thereof is received by a two-dimensional light-receiving element. A light-receiving amount distribution obtained by the light-receiving element is amplified by an amplifier, and then converted to digital waveform data. Based on a peak position of this waveform data, a sectional shape of the workpiece is detected.
However, in the above optical displacement meter, light with which the workpiece has been irradiated may be reflected more than once on the surface of the workpiece. The light reflected more than once is incident on the light-receiving element, to cause appearance of a plurality of peaks in the waveform data. This prevents acquirement of an accurate sectional shape of the workpiece.